Abstract: Ultrasonic motors,as a fractional horsepower motor of new type,have attracted scholars'attention.Inthis paper,we have developed a motion modeling of projection-teeth of traveling wave ultrasonic motors,which issignificant for an expansion of interface modeling between the rotor and stator.At the same time,relationship betweenteeth height and displacement of a contact point,resonant frequency,is obtained by using the Finite Element Method (FEM) corresponding to various vibration modes.It is found that teeth height,from 3 mm to 9 mm,has great impacton displacement along circumferential direction,specially for (9,0) vibration mode,while displacement along radialdirection tends to saturation for teeth height of about 6 mm.Based on the motion modeling of projection-teeth,wefabricated an ultrasonic motor with 3-D interface of new type.